title: Domain inhibitory and bacteriostatic activities of the five-domain Kazal-type serine proteinase inhibitor from black tiger shrimp Penaeus monodon.
abstract: Serine proteinase inhibitors (SPIs) in multi-cellular organisms are important modulators of proteinase activities in various biological processes. A five-domain Kazal-type SPI SPIPm2 from the black tiger shrimp Penaeus monodon is presumably involved in innate immune response. The SPIPm2 with the domain P1 residues T, A, E, K and E was isolated from the hemocyte cDNA libraries and found to strongly inhibit subtilisin and elastase, and weakly inhibit trypsin. To unravel further the inhibitory activity of each domain, we subcloned, over-expressed and purified each individual SPI domain. Their inhibitory specificities against trypsin, subtilisin and elastase were determined. Domain 1 was found to be inactive. Domains 2, 3 and 5 inhibited subtilisin. Domain 2 inhibited also elastase. Domain 4 weakly inhibited subtilisin and trypsin. The intact SPIPm2 inhibitor was found to possess bacteriostatic activity against the Bacillus subtilis but not the Bacillus megaterium, Staphylococcus aureus, Vibrio harveyi 639 and Escherichia coli JM109. Domains 2, 4 and 5 contributed to this bacteriostatic activity.
authors.affiliation: Shrimp Molecular Biology and Genomics Laboratory, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Suchao
authors.initials: S
authors.lastname: Donpudsa
authors.forename: Anchalee
authors.initials: A
authors.lastname: Tassanakajon
authors.forename: Vichien
authors.initials: V
authors.lastname: Rimphanitchayakit
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001483:Base Sequence; D006434:Hemocytes / Q000276:immunology / Q000378:metabolism; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors; D033561:Penaeidae / Q000201:enzymology* / Q000235:genetics; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D020860:Subtilisin / Q000037:antagonists & inhibitors; D014357:Trypsin / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D011994:Recombinant Proteins; D015842:Serine Proteinase Inhibitors; D010196:Pancreatic Elastase; D014357:Trypsin; D020860:Subtilisin